edit (too deep to reply): I really don't think it's moving the goal posts, you asked about redirecting that food production in general, not soy. As is mentioned elsewhere, the soy oil isn't really used much for food anyway.

That said - you can't just swap corn grown for ethanol for "corn for people to eat" - the equipment involved to harvest it is completely different, as are the facilities to process it. The same concerns apply to other crops.

Farmers currently produce as much food as the market demands, plus some excess capacity is converted biofuels. If the market required less, they would (eventually) produce less unsubsidized food. Then, the logic goes, WW3 takes out a lot of our food and we suffer massive shortages because there is no extra capacity to produce more.